The process steps conventionally used for the manufacture of ferrite ceramics, such as manganese-zinc ferrites and nickel-zinc ferrites, have been established for many years. In such conventional processes for the manufacture of polycrystalline ferrites, measured amounts of metal oxides or metal carbonates are mixed together and pulverized. The pulverized materials are calcined at temperatures up to 1000.degree. C. to initiate solid-state diffusion and formation of the desired spinel-type crystal structure. Further milling prepares the powder suitable for pressure compaction into components which are sintered and then further densified in a hot press procedure. Because the starting materials are dry, such procedure has been termed a "dry" process for the manufacture of ferrite components. Certain limitations are inherent in such dry processing of materials. The desired homogeneity is limited by mechanical mixing and pulverizing. Precise product composition is difficult with such dry processing. The impurity content is not readily controllable.
The "dry" process was replaced by a "wet" process wherein the constituents of the ferrites are co-precipitated from solution. Better homogeneity resulted. Precipitation from a solution made from metal salts in itself is not sufficient to overcome deficiencies. It is known to use carbonate or hydroxide constituents for the co-precipitation of the metal particles. The ferrite particles produced were sufficient in density and homogeneity to produce a workable ferrite ceramic for magnetic heads. However, the ferrite powder and the resultant ferrite blocks produced were not dense enough for use in magnetic heads to reproduce the higher frequency recording information required of present day technology. The former processes produced a small amount of impurities and voids in the resultant ferrite blocks, but these impurities and voids were significant, especially in the deposition of thin film layers of material used in the transducers of higher technology magnetic heads.